30 
U.S. P.  Chemicals  and  Tests. 
f  Am.  Jour.  Pharm. 
\    January,  1910. 
the  ton,  to  mill  it  to  a  fine  powder,  and  still  obtain  an  absolutely  clear 
solution. 
Deterioration  is  another  condition  which  arises  where  the  natural 
and  unavoidable  change  in  many  chemicals  is  concerned.  Alka- 
loids, for  instance,  when  subjected  to  light,  or  by  age,  change  color 
yet  may  not  lose  any  of  their  efficiency,  whereas,  on  the  other  hand, 
such  chemicals  as  sulphites,  ammonium  carbonate,  etc.,  are  undoubt- 
edly considerably  affected  by  such  changes  which  occur  in  spite  of 
all  precautions.  It  is  evident  that  the  manufacturer  cannot  guard 
against  such  deteriorations,  since  they  follow  natural  courses,  but 
can  only  protect  himself  as  far  as  possible  by  applying  chemical 
knowledge  and  good  common  sense. 
A  few  comments  on  some  of  the  Pharmacopoeia  tests  may  be  of 
interest : 
Acetphenetidin. — To  determine  the  presence  of  acetanilid, 
acetphenetidin  is  boiled  with  sodium  hydroxide,  the  solution  cooled, 
agitated  with  chlorinated  soda  solution,  when  a  clear  yellow  liquid 
should  result,  and  not  a  purplish  red  or  brown  red  cloudy  liquid  or 
precipitate.  Nevertheless,  when  making  this  test  a  precipitate  is 
obtained,  indicating  the  presence  of  acetanilid,  although  it  could  not 
be  found  by  the  bromine  or  other  tests. 
Acid  Acetic,  Glacial. — The  test  for  empyreumatic  substances  is 
very  strenuous.  It  is  required  that  the  tint  produced  by  the  addition 
of  two  drops  of  one-tenth  normal  potassium  permanganate  solution 
to  2  c.c.  of  the  acid,  diluted  with  10  c.c.  of  water,  should  not  be 
changed  to  brown  within  two  hours.  The  German  Pharmacopoeia 
requires  that  when  5  c.c.  of  acid  in  15  c.c.  of  water  are  mixed  with 
1  c.c.  permanganate  of  potash  solution  (1-1000)  it  should  not  lose 
its  red  color  within  ten  minutes. 
Calcium  Bromide. — If  a  quantity  of  this  salt  is  used  in  testing 
for  bromates,  and  only  a  drop  of  diluted  sulphuric  acid,  a  yellowish 
color  may  be  developed,  but  in  such  instances  bromates  could  not 
be  detected  by  any  further  tests.  However,  if  the  salt  is  covered 
with  diluted  sulphuric  acid  no  color  results. 
Calcium  Phosphate. — The  limit  for  chlorides  is  exceedingly 
difficult  to  attain. 
Cinchonine  Sulphate. — It  is  stated  that  one  part  is  soluble  in 
69  parts  of  chloroform  at  25 0  C,  and  further  on  there  is  a  require- 
ment that :  "  If  one  part  of  the  powdered  salt  be  macerated  with 
frequent  agitation  in  80  parts  of  chloroform,  at  ordinary  tempera- 
